In the construction industry, it is nowadays a conventional operation to add insulating materials to the inner walls of a room, ceiling, crawl space, basement or exterior wall of a building. Such insulating materials may be installed for their sound-proof features: this is often the case in rooms of high-class, high-rise commercial buildings, for privacy of communications between the occupants. Alternately, or concurrently, such insulating materials may be installed for their thermal shielding features: this insulation is necessary in all the exterior walls of buildings located in countries, such as Canada, where winter months are very cold.
Such insulating materials are mounted between the vertical and horizontal studs making the wall frame. Batts or flexible glassfibers are often used. Previously such batts were adhered to one or two paper sheets which served as a means to secure the batts in place. However, paper covering is now discontinued for fire prevention.
It is well known that, if not secured in place, batts of glassfibers, being of a flexible nature, tend with time to sag or drop from their original position in the cavity of the wall in which they are embedded; this is increasingly so with increasingly thicker batts.
There are many reasons why flexible insulating batts drop in their wall cavity. Some of the most common reasons are due to job conditions during construction, vibration, moisture, and water absorbed due to natural atmospheric conditions and job hazards, use of inadequate support members, and many other on-the-job conditions where friction-fit products cannot perform as required. The problem is greater in the case of walls of a height exceeding eight feet, whether partition walls or peripheral walls.
Of course, insulation sagging means loss of thermal or sound insulation in the exposed areas. To the quality-of-work conscious construction worker, this is not acceptable.
Attempts have been made in the art to tackle this problem. Generally, such improvements include either glueing the batts to a backing surface or securing metal strips transversely and in vertically-spaced-apart fashion as add-on elements to the wall frame, the strips being provided with sharpened prong members adapted to engage into the insulating batts, in order to more securely hold the batts in position.
Glueing or installation of add-on transverse strips require additional labour and inspection. Also the strips cannot retain the edges of the batts.